1. Field of the Invention
This invention relates to a terminal block assembly including a terminal block member having a bus bar provided with knife edge means for penetrating the insulation of an insulated conductor that is carried by a support member, whereby during the connection of the conductor support member with the terminal block member, the insulation layer is penetrated by the knife edge to effect an electrical connection between the bus bar and the conductor. In order to provide a mechanical advantage during the connection of the conductor support member with the terminal block member, the support member and the terminal block member are provided with associated openings that cooperate to define a long-arm lever arrangement affording a mechanical advantage to assist in connecting the members together.
2. Brief Description of the Prior Art
As disclosed, for example, by the French patent No. 2,516,711, it is known in the patented prior art to provide a contact activation piece having catch surfaces for the insulated conductor and that can be shifted within the interior of the insulation material housing of the terminal block between conductor insertion position and a contacting position in which the conductor is pressed into engagement with the displacement contact that penetrates the conductor insulation. In the insulation material housing that is closed off upward, there is an insertion opening for the conductor, which is adjoined by guide means that extend all the way into the area over the displacement contact, and furthermore, there is provided a wide, essentially V-shaped passage and support opening for a tool, for example, a screwdriver, that is operable to shift the contact activation piece. Under this opening in the insulation material housing, there is arranged another insertion and support opening in the movable contact activation piece. The arrangement is so made that the contact activation piece is initially held with the tool in the conductor insertion position in which the conductor can be inserted into the contact activation piece, while the tool is supported on one of the oblique surfaces of the opening in the housing that faces toward the conductor. The tool is then turned into the opposite oblique position in the other oblique surface of the opening in the contact, and the contact activation piece is then forced with the lower end of the tool supporting the tool on the oblique surface in the upper wall of the housing exerting manual force over the displacement contact, while the conductor is contacted in an insulation-penetrating manner, with corresponding action.
In particular, in the case of conductors with larger diameters, by no means inconsiderable forces have to be supplied in this kind of insulation-penetrating contact making procedure. The previously known design here is problem-prone inasmuch as unfavorable lifting conditions result for the supply of the force required to achieve the necessary insulation-penetrating contact with the conductor. The pivotal point, so to speak, is the bracing of the tool on one limiting surface of the opening on top in the housing with a first lever arm up to the end of the tool in the contact activation piece and, with the other lever arm, above the housing, all the way to the handle of the tool. In this design, during the press-in phase, there is also an extremely unfavorable force-consuming, practically useless force component that considerably stresses the upper, thin-wall and rather unstable area of the insulation material housing. Moreover, under these leverage conditions, the activation tool must also be impacted manually with a force component pointing downward. Nevertheless, the lower end, for example, the sharp-edged end of a screwdriver in the receiving opening of the contact activation piece, easily migrates upwardly and, after repeated activation, causes damage here. Moreover, in this design, the tool has a considerable pivot arc distance and collides in the conductor insertion position easily with the inserted conductor.